Tractor carried rotary cultivator or mower for cutting around posts, etc.



March 11, 1958 VA OLSON 2,826,129

TRACTOR CARRIED ROTARY CULTIVA'LOR OR MOWER FOR CUTTING AROUND POSTS,ETC j I 5 Sheets-Sheet l F:I .led Sept. 15, 1955 J8 v INVENTOR.

flrwldl. 0516 r BY 7 March 11, 1958 A. L. OLSON 2,

TRACTOR CARRIED ROTARY CULTIVATOR 0R MOWER FOR. CUTTING AROUND POSTS,ETC

Filed Sept. 15, 1955 5 Sheets-Sheet 2 43 4% 4 5% 5 7 l INVENTOR.

5 47 4f 4i Arwhfi fll s ozz -March 11,- 1958 A. L. OLSON 2,826,129

' TRACTOR CARRIED ROTARY CULTIVATOR 0R MOWER vFOR CUTTING AROUND POSTS,ETC Filed Sept 13, 1955 5 Shegts-Sheet 3 INVENTOR.

Arrakmfr March 11,1958 A. L. OLSON 2,826,129

TRACTOR CARRIED ROTARY CULTIVATOR OR MOWER FORCUTTING AROUND POSTS, ETC

Filed Sept. 13, 1955 5 Sheets-Sheet 4 A INVENTOR. flzvza/al. 0%

March 11, 1958 A. L. OLSON 2,826,129-

TRACTOR CARRIED ROTARY CULTIVATOR OR MOWER FOR CUTTING AROUND POSTS, ETC

INVENTOR.

2,826,129 Patented Mar. 11, 1958 TRACTOR CARRIED RGTARY CULTIVATOR ORMOWER FUR CUTTING AROUND POSTS, ETC.

Arnold L. Olson, Wahpeton, N. Dale Application September 13, 1955,Serial No. 534,015 20 Claims. (Cl. 9740) My invention relates broadly toa novel and improved agricultural implement. In particular, it relatesto a novel and improved mowing and/or cultivating implement adapted tobe connected to and carried by a tractor.

The primary object of my invention is to provide a novel and improvedagricultural implement which when attached to a tractor or the like isadapted to cultivate or mow completely around trees, shrubs, fenceposts, and like obstructions, While driving past the obstruction andwithout stopping or interruption. My invention is adapted to eliminateall hand cultivating or trimming around trees, shrubs, posts and thelike.

Another object of my invention is to provide a device of the classdescribed which is simply and effectively operative, and simple andrugged in construction.

Another object of my invention is to provide an agricultural implementadapted to be connected to and carried by a tractor or the like andwhich may be provided with rotary cultivating or mowing implement headswherein the rotary heads of the implement form a part of a lower unitwhich tends to rotate about a vertical axis upon rotation of the heads;the lower unit is locked against said planetary rotation about saidvertical axis during normal straight running, however when a tree, postor a like obstruction is approached, the lower unit is released forplanetary rotation and the rotating implement heads revolve togetheraround the tree or obstruction cultivating or trimming thereabout,without ever having stopped or slowed the forward movement of thetractor, and the lower unit is then again relocked automatically againstplanetary rotation.

Another object of my invention is to provide in a device of the classdescribed, means for automatically releasing the lower unit forplanetary rotation when a tree, post or a like obstruction is in thepath of the implement.

Still another object of my invention is to provide in a device of theclass described, control means which will automatically trip thelatching mechanism which locks the lower unit against planetaryrotation, if an obstruction, such as a rock or the like, is met by oneof the rotating heads and which puts an undue load on the lower unit,thereby effecting rotation of the lower unit and heads and avoiding theobstruction.

A further object of my invention is to provide in a device of the classdescribed, means for absorbing the shock of stopping planetary rotationof the lower unit and relocking it against such rotation.

These and other objects and advantages of my invention will becomeapparent from the following specification and claims, references beinghad to the accompanying drawings wherein:

Fig. 1 is a view in top plan of my invention showing it attached to atractor in normal operative position;

Fig. 2 is a view in front elevation of the structure shown in Fig. 1;

Fig. 3 is an enlarged view in vertical section taken substantially onthe line 3-3 of Fig. 1;

Fig. 4 is an enlarged fragmentary view partly in horizontal section andpartly in plan taken substantially on the line 4-4 of Fig. 2; I

Fig. 5 is a fragmentary view of a part of Fig. 4 showing some of theparts thereof in different positions;

Fig. 6 is an enlarged fragmentary view in top plan of a portion of Fig.I;

Fig. 7 is an enlarged fragmentary view in side elevation takensubstantially on the line 77 of Fig. 1;

Fig. 8 is a fragmentary view in top plan of a modification of myinvention;

Fig. 9 is a fragmentary view partly in elevation and partly in sectiontaken substantially on the line 9--9 of Fig. 8;

Fig. 10 is a view in top plan, with some parts being broken away, ofanother modification of my invention;

Fig. 11 is a view in side elevation of the modification of my inventionshown in Fig. 10, as viewed substantially on the line 1111 of Fig. 10;

Fig. 12 is a fragmentary view in top plan of the structure of Fig. 10,showing some of the parts thereof in different positions;

Fig. 13 is an enlarged view partly in top plan and partly in horizontalsection of a stop construction shown in Fig. 10; and

Fig. 14 is an enlarged detail view partly in elevation and partly insection taken substantially from the line 14-14 of Fig. 10.

Referring more particularly to the drawings, wherein like parts will beindicated by the same numeral, my novel and improved agriculturalimplement comprises a supporting structure, indicated generally by thenumeral 10, which is adapted to be connected to a tractor, indicated inits entirety by the letter A. By the use of the term tractor I ambroadly referring to any motor-driven wheeled device of any suitableconstruction adapted for carrying an agricultural implement, and it isnot necessaw that it have a seat or be of the specific structure shownin Figs. 1 and 2. Reference to an agricultural implement herein is notintended to be limited to an implement used in the cultivation, raisingor growing of a crop in the limited extent of a harvestable product, butis also intended to include an implement for mowing or trimming grass,weeds, and the like.

Supporting structure 10 includes a supporting bar 11, which ispreferably an elongated angle iron as shown having a pair of pintles 12rigidly anchored thereto, by welding or the like, one at each of itsends in axially aligned relationship. Suitable brackets 13 are bolted orotherwise rigidly anchored to the tractor A and have laterally outwardlyprojecting portions which journal pintles 12 and mount supporting bar 11onto tractor A in a generally horizontal position generally parallel tothe path of straight-line movement of tractor A forpivotally swingingmovements about the generally horizontal axis of aligned pintles 12.Tubular members 14 and 15 of supporting structure it) are each rigidlyanchored at one end by welding or the like to supporting bar 11 and theyproject laterally outwardly therefrom, the latter generallyperpendicular to supporting bar 11 and the former generally diagonallyinclined toward the latter, to be rigidly connected at their oppositeends to a housing 16, which is at the free end of supporting structure10 and disposed laterally outwardly beyond the limits of tractor A.

Housing 16 has an annular inwardly projecting boss 17 which supports abearing 18 for the uppermost end 19 of a normally vertically disposeddepending shaft 20. Housing 16 encloses bevel gears 21 and 22, theformer being connected to shaft 20 and the latter being con nected tothe end of the drive shaft 23. Drive shaft 23 extends through tubularmember 14 and is adapted to be connected to and driven from the powertakeoff of tractor A. Drive shaft 23 and bevel gears 21 and 22 drivedepending shaft about a normally vertically disposed axis.

1 provide arm structure, indicated generally by the numeral 24, whichcomprises a hub 25 and a pair of normally horizontally disposed arms 26.Preferably hub 25 has a web portion 27 housing a bearing 23, whichjournals hub 25 on depending shaft 20 for rotation with respect theretoabout the normal vertical axis of rotation of shaft 20. Arms 26 arerigidly anchored to hub 25 by bolts or the like and project radiallyoutwardly there from in diametrically opposed relationship. Each of thearms 26, in the embodiment of my invention shown in Fig. 3, is hollowand tapers to a cylindrical tip portion 29. Hub portion 25 is generallytube-like with web portion 27 thereof disposed intermediate its ends. Aremovable bottom cover plate 30 is bolted by screws or the like to theopen bottom end of hub portion 25 to define therewith, between webportion 27 and cover plate 30, an enclosed gear housing chamber 31. Gearhousing chamber 31 contains a bevel gear 32, which is rigidly connectedto the lower end of depending shaft 20 to be driven thereby, and a pairof oppositely disposed bevel gears 33 meshed with gear 32 to be driventhereby in opposite directions. Each of the gears 33 is connected to adifferent one of a pair of normally generally horizontally disposedaxially aligned shafts 34, which project radially outwardly indiametrically opposite directions from gear housing 31, each through adifferent one of the arms 26. Each of the shafts 34 comprises sections35 and 36 having adjacent ends connected by a coupling 37. Sections 36of shafts 34 are journalled in hub portion 25 by anti-friction bearings,indicated by the numeral 38, and sections 35 of shafts 34 are journalledin cylindrical tip portions 29 of arms 26; whereby, each of the shafts34 are rotatable within a different one of the arms 26 about ahorizontal axis independent of arm structure 24. Each of the shafts 34terminates at the free radially outwardly disposed ends of sections 35thereof in a reduced threaded portion 39, which receives a nut 40 forfastening a cup-shaped web member 41 to each of the shafts 34 forrotation therewith. Each of the web members 41 has a generallycylindrical flange portion 42 which is rigidly connected, by welding orthe like, to one of a pair of implement heads 43. Implement heads 43comprise generally elongated tubular structures disposed in axiallyaligned relationship, and each head 43 encompasses a different one ofthe arms 26 in concentric relationship with the shaft 34 to which it isconnected for rotation through one of the web members 41.

Implement heads 43 might be formed in the nature of the mowing blades orknives of a reel-type lawn mower; however, as specifically shown, theycomprise cultivating heads having tubular bodies 4-; and a plurality oflongitudinally and circumferentiaily spaced cultivating lugs 45 anchoredto the tubular body 44 and projecting radially outwardly therefrom.

Each of the cup-shaped web members 41 supports a pair of axially spacedball bearings, indicated by the numeral 46, for supporting the implementheads 43 on arms 26 for rotation therewith and for rotation with shafts34 independent of arm structure 24. Thus, in the embodiment of myinvention shown Figs. 1 through 7, the implement heads 2 3 arerotatable, with a different one of the shafts 3 5, about alignedhorizontal axes in opposite directions, as shown by the arrows in Fig. 2independent of the arm structure 24 and are capable of planetarymovement with arm structure 24 about the vertical axis of dependingshaft 24 I provide a pair of annular sealing members 47, one of which isassociated with each of the web members 41 at the radially inwardlyopening end thereof to seal in the bearings 46. Annular sealing members47 are held against axial movement by the shoulders 43 between thecylindrical tip portion 29 and the tapered portion of each of the arms26.

Referring in more detail to certain elements of the specific structureof my invention shown particularly in Fig. 3, housing 16 includes agenerally cylindrical normally vertically disposed neck portion 49,which encompasses depending shaft 20 in coaxial relationship, and aradially outwardly projecting normally generally horizontal annularflange 50, which is preferably integral with neck portion 49 at thelower end thereof. Flange St) is rigidly anchored, by bolts or the like,to a generally rectangular flat supporting member 51, normallyhorizontally disposed, which has a depending centrally disposed annularboss 52 rigid therewith and preferably formed integrally therewith. Afiat supporting member 53 is rigidly connected, by bolts or the like, toa normally generally horizontal radially outwardly projecting annularflange 54A formed at the upwardly opening end of hub portion 25.Supporting member 53 is similar to supporting member 51 and is disposedin vertically downwardly spaced relation therewith, closely adjacentboss 52. Flat supporting member 53 has a central normally upwardlyprojecting boss or hub 54 rigid therewith and preferably formedintegrally therewith. Hub 54 encompasses depending shaft 20 in coaxialrelationship radially inwardly disposed with respect to boss 52. Shaft20 is journalled in hub 54 for rotation with respect thereto and ananti-friction bearing indicated by the numeral 55, between boss 52 andhub 54 journals the latter for rotation with respect to boss 52 aboutthe axis of depending shaft which aids in supporting arm structure 24for rotation about the axis of depending shaft 20 independent of therotation of shaft 20 and which provides a very compact and rigidconstruction. Depending shaft 26 is further supported for rotation withrespect to housing by anti-friction bearing 56 in neck portion 4).

The rotation of implement heads 43 in opposite directions tends torotate arm structure 24 about the axis of depending shaft 26) in thedirection of the arrows shown in Fig. 1 due principally to the frictionof the implement heads 43 with the work. I provide releasable indexingmeans for selectively locking arm structure 24 against such rotation.

My indexing means is preferably a spring detent mechanism havingcooperating elements carried by relatively movable supporting members 51and 53, the latter being rigidly connected to arm structure 24 and theformer being rigidly connected to supporting structure 10.

Specifically, referring first to Fig. 4, I provide a pair of latchingelements 57 which are longitudinally extended arms bifurcated at theirends 58. At their opposite ends, arms or latching elements 57 arepivotally connected by bolts 59, or the like, to generally rectangularflat supporting member 53 to be disposed generally parallel to oppositesides and adjacent oppositely disposed corners thereof, wherein they arecircumferentially spaced in a manner subsequently explained. Arms 57 aredisposed between supporting members 51 and 53 and pivotally swingable inplanes parallel thereto between latching positions and inoperativepositions. I provide a pair of rods 60 which are disposed in laterallyspaced normally generally parallel relationship to each other andgenerally perpendicular to arms 57; and each rod 60 is disposed adjacenta different one of the opposite edges 61 of mounting member 53. Mountingmember 53 has a pair of outwardly projecting lugs 62 anchored thereto bywelding or the like at the two opposite corners thereof which arelaterally spaced from arms 57. Each of the rods 60 has an outwardlyprojecting car 63 rigidly anchored thereto intermediate its ends, bywelding or the like, and each of the cars 63 is pivotally connected to adifferent one of the lugs 62 by any suitable means. Each of the rods 6%has a pair of spaced parallel lugs 64 and 65 rigidly connected thereto,by welding or the like, to form a guide channel receiving the adjacentedge 61 approximately centrally thereof. Lugs 64 and lugs 65 aid insupporting and guiding rods 60 for the pivotal movement thereof. Each ofthe ears 63 has a laterally inwardly projecting finger portion 66, whichengages a part of the lug 62 to which it is pivotally connected forlimiting laterally outwardly swinging movements of its associated rod60. When each of the fingers 66 is in engagement with its associated lug62, rods 60 are at their limit of outwardly swinging movement and are inthe positions shown in Fig. 4, which will be defined as the inoperativepositions of rods 60. As shown in Fig. 4, rods 60 are parallel to edges61, laterally outwardly spaced therefrom, at their inoperativepositions. I provide resilient means comprising a pair of coilcompression springs 67, one of which is associated with each of the rods60 for biasing it to its inoperative position. Referring in particularto Fig. 7, each of the compression springs 67 underlies supportingmember 53 laterally spaced from the pivotal axis of its associated rod60; and specifically springs 67 are adjacent the opposite ends of edges61 from the pivotal connections of rods 60. Each spring 67 encompasses asupporting rod or pin 68 which is connected at one end to the associatedrod 66 and at its opposite end is longitudinally slidable in a dependingbracket 69 which is rigidly connected, by any suitable means, to theunder side of supporting member 53. Compression springs 67 are disposedgenerally perpendicular to their associated rods 60; and each of therods 60 is pivotally swingable from its inoperative position, Fig. 4,against the bias of its associated spring 67, laterally towardsupporting member 53 about its pivotal connection thereto, to theposition shown in Fig. 5.

A pair of spring biased toggles, indicated generally by the numeral 70,are disposed generally parallel to rods 60 and generally perpendicularto arms 57; and each of the toggles 70 is associated with one of therods 60 and a different one of the arms 57 to control, in conjunctionwith its associated rod 60, the movement of its associated arm 57between its latching position and its inoperative position. Each of thetoggles 70 comprises a pair of links 71 and 72 having adjacent endspivotally connected. The free end 73 of link 71 is pivotally connectedto its associated arm 57 intermediate the ends of the latter; and thefree end 74 of link 72 is pivotally connected to a supporting boss 75,which is rigidly anchored to the upper side of supporting member 53. Oneof a pair of torsion springs 76 is associated with each of the toggles70. Each spring is connected at a looped intermediate portion thereof tosupporting member 53 adjacent the pivotal connection of link 72 and boss75 of its associated toggle 70. One end of each spring 76 engages anarcuate ofiset portion 77 of the adjacent link 72 and the other endengages the adjacent boss 75; wherein, each spring 77 biases itsassociated toggle 70 just past dead center, as shown in Fig. 4. At thisposition link 72 abuts an inwardly projecting finger portion 78 of theadjacent lug 64. Lugs 64 are at their limit of outward movement when therods 60 are at their inoperative positions, as shown in Fig. 4. Tensionsprings 76 biasing toggles 70 each against one of the lugs 64, aidscompression springs 57 in biasing rods 60 to their inoperativepositions. Rods 60 are pivotally swingable from their inoperativepositions, each toward the supporting member 53 to actuate itsassociated toggle 70 and thereby move the associated latching element orarm 57 from its latching position to its inoperative position. Thisoperation will be discussed in more detail subsequently. it will beremembered that arms 57 are connected to arm structure 24 for rotatablemovement therewith about the axis of depending shaft 20, and I provide acooperating latching element 79, see Fig. 7, which is a bar pivotallyconnected intermediate its ends to lug 88, which is rigidly anchoredadjacent one corner of the supporting member 51. Bar or latching element79 is pivotally swingable about the horizontal axis indicated by thenumeral 81 between the full line and dotted line positions shown in Fig.7. At the full line position of bar 79, it is generally verticallydisposed; and its lower end is disposed in the path of travel of thebifurcated ends of arms 57, during the rotational movement of arms 57'with arm structure 24. Each of the bifurcated ends of arms 57 journals aroller 82 which engages the lower end of bar 79, when the latter is inits full line position of Fig. 7, to lock armstructure 24 at an indexedposition.

I provide manual control means, indicated generally by the numeral 83for moving bar 79 to its dotted line position, Fig. 7, to release thelatching engagement between bar 79 and one of the arms 57; and thuspermit the rotation of arm structure 24 frorn one index position to thenext. Manual control means 83 comprises a generally Lshaped actuatinglever 84 which is pivotally connected at the intersection of its armportions 85 and 86 to upstanding lug 87, which is rigidly anchored bywelding or the like to supporting member 51. Arm portion 86 liesadjacent a toggle 88, pivotally connected at one end to the upper end ofbar 79 and pivotally connected at its opposite end to lug 89 which isrigidly anchored to mounting member 51 adjacent lug 87. Toggle 88 has anofiset portion 90 which overlies the free end of arm portion 86. Toggle88 is biased just pastdead center by a tension spring 91, the full lineposition shown in Fig. 7, whereat arm portion 86 is generallyhorizontally disposed with a depending leg 92 thereof, at its free end,in abutment with supporting member 51. It is clear that the pivotalmovement of actuating lever 84 moves arm portion 86 thereof generallyupwardly to move toggle 88, against the bias of spring 91, and therebypivotally swing bar 79 so that the lower end thereof is disposedlaterally outwardly of the path of movement of latching elements or arms57. This movement is shown clearly by dotted lines in Fig. 7. To actuatelever 84, I provide a rod 93 extending between the free upper end of armportion 85 and a pie-shaped plate-like bell crank 94 connected at itsapex to housing 16 for pivotally swinging movements about the axis,indicated by the numeral 95. A rope 96 is connected at one end to hellcrank 94 and its opposite end is connected to a second bell crank 97,which is actuated by rod 98. Rod 98 is connected for longitudinalmovement to the tractor A by a bracket 99; and rod 98 is connected to ahandle member or the like disposed within easy reach of the tractoroperator so that actuation of said handle member moves rod 98longitudinally generally rearwardly, which, in turn, moves bell crank 94to the dotted line position shown in Fig. 6 through the connectionthereto by means of hell crank 97 and rope 96; and movement of bellcrank 94 to its dotted line position moves actuating lever 84 to itsdotted line position through connecting rod 93.

I provide a piston cylinder arrangement, indicated generally by thenumeral 100, between tractor A and upstanding lug 101 rigidly anchoredto the top of housing 16 to pivotally swing supporting structure 10 fromits normally generally horizontal position, about the axis of alignedpintles 12, to an inoperative upwardly projecting position, not shown inthe drawings. It is clear that when supporting structure 10 is in itsinoperative position, arm structure 24 and implement heads 43 areupwardly raised to inoperative positions; wherein implement heads 43 areno longer in contact with the ground; and my novel and improvedagricultural implement may be easily transported by the tractor A to theplace where work is to be done. The drawings show the elements of myinvention in their normal positions, wherein the implement heads areadapted to perform their cultivating or mowing function.

Referring now to the operation of my invention hereinbefore described,latching elements or arms 57 are normally maintained at their latchingpositions, each by its associated spring biased toggle 70, andcooperating latching element or bar 79 is normally maintained, by itsassociated spring biased toggle 88, within the path of travel of thebifurcated ends 58 of arms 57 and the rollers 82 carried thereby;wherein bar 79 is engaged by one of the rollers 2 to locl; arm structure24 against rotation and which defines one indexed position of armstructure 24. This condition is shown in the drawings, and particularlyin Figs. 1 and 2; and it should be noted that at this indexed position,the rod 60 which is associated with the arm 57 in latched relationshipto bar 79 is dis posed forwardly of arm structure 24, and in factforwardly of all other parts of my novel and improved implement whichare disposed laterally outwardly of the limits of tractor A; wherein,this forward rod 60 is in position to be first contacted by any obstaclewithin the path of my novel and improved implement during forwardmovements of tractor A. it will also be noted that this forward rod 60is disposed generally perpendicular to the path of travel of tractor Aand is pivotally connected to mounting plate 53 laterally inwardly ofthe axis of rotation of arm structure 24, and specifically at thelaterally inwardly disposed forward corner of supporting member 53. Atthis indexed position, my agricultural implement is operated forordinary straight running with arm structure 24 locked against rotation;however, implement heads 43 are rotated independently of arm structure24 from power takeoff of tractor A for mowing or cultivating, dependingupon which type of implement head is used, a generally straight swath.When an obstacle, such as a tree, post or the like is disposed withinthe path of my agricultural implement, generally centrally with respectthereto, it is engaged by the forward rod 60 laterally outwardly of thepivot axis thereof, Which engagement, during forward movements of thetractor A, moves said forward rod 60 from its inoperative position aboutits pivot axis toward the adjacent edge 61 of supporting member 53 andtowards its associated toggle 70; wherein, finger portion 78 of the lug64 anchored to forward rod 60 actuates the associated toggle 70 to movethe latched arm 57' from the latched position shown in Fig. 4 to thefull-line position shown in Fig. 5. This actuation of toggle 70 byfinger portion 78 past dead center breaks the holding force of toggle7%); wherein, the force, effected by the rotation of implement heads 43in opposite directions in engagement with the work, tending to rotatearm structure 24, about the axis of depending shaft 20, in the directionindicated by the arrow in Fig. l, breaks toggle It? further, to move thelatched arm 57 radially inwardly of latching bar 79, with respect to theaxis of rotation of arm structure 24, and out of latched engagementtherewith to an inoperative position, as shown in dotted lines in Fig.5. The automatic releasing of the latched engagement of bar 7? and arm57 permits the rotation of arm structure and after the rotation of thefirst released arm 57 past bar 79, the former is returned by itsassociated spring biased toggle 70 to its latched position.

After the automatic releasing of the latched engagement of bar 79 andone of the arms 57, arm structure 24 will rotate until the other arm 57engages bar 79 in latched engagement, or between two indexed positions.Arms 57 are circumfercntially spaced 180 so that arm structure 24 willrotate 180 between two indexed positions. During the rotation of armstructure 24, implement heads 43 rotate therewith 180 about the obstaclewhich actuated the foremost rod 60 without ever having stopped or sloweddown the tractor A. The two implement heads 43 continue theirindependent rotation during planetary rotation thereof with armstructure 24 so that each, revolving l80 around the obstacles, togethercultivate or trim approximately a full 360 thereabout. After rotatingabout the obstacle, arm structure 24 and implement heads 43 are againlocked at an indexed position and are again ready for ordinary straightrunning. When the latching elements of my indexing means are released topermit rotation of arm srtucture 24 and implement heads 43 through one180 cycle, the oppositely rotating implement heads 43 cause the armstructure 24 and implement heads 43 to rotate rapidly about theobstacle, which places the other rod 60 in the foremost position readyto automatically release its associated arm 57 from latched engagementwith bar '79, and ready for the next obstacle and another cycle ofplanetary rotation,

I provide the manual control means 33, in addition to the automaticcontrol means comprising rods 60 and toggles 70, in case an obstacle isapproached which is not properly positioned to actuate the foremost rod69; for example, a low bush or post. The operation of manual controlmeans 83 is simply effected by the operator merely pulling and releasingrod $8 by any suitable handle member, which efiects the movement oflever 84- to break toggle 88 past dead center and move bar 79 from itsfull-line position to its dotted line position shown in Fig. Thisreleases the latching elements, bar 79 and one of the arms 57, to effectthe 180 cycle of rotation of arm structure 24 and implement heads 43.

Although I have shown a preferred embodiment of my indexing means, andboth manual and automatic control therefor, it is clear that there mightbe many modifications [0 this; for example, each cycle of rotation ofarm structure 24 and implement heads 53 might be 360 instead of 180,which would require only one latching arm 57 and automatic control meanstherefor. in addition, although arms 26 of arm structure 24 andimplement heads 43 are shown generally perpendicular to the path ofmovement of tractor A at an indexed position, they might be inclinedthereto to eliminate an uncut or uncultivated space between the twoimplement heads 43.

i provide a modification of my invention, shown in Figs 8 and 9, whichis substantially the same as my invention previously described, butwhich differs in com prising rotary cultivating or mowing elements. Theelements of this modification which are exactly the same as previouslydescribed will be given the same numerals in Figs. 8 and 9 as usedpreviously and will not be further referred to; the elements which aresubstantially the same will be indicated by the same numeral butdistinguished by a subindex letter. The diametrically opposed arms 26aof arm structure 24 are axially aligned generally cylindrical tubes; andeach has a web portion 1% transversely disposed therein intermediate itsends and ri idly anchored thereto for journaling shaft sections 36a. iprovide a pair of depending bearing bosses; and each is rigidly anchoredto a ditferent one of the arms 26a at the free end thereof. Bearingbosses 1G1 each journal one of a pair of normally vertically disposedstub shafts 182, each of which is rigidly connected at its lower end toan implement head 43a, which comprises a pair of diametrically opposedradially outwardly projecting normally generally horizontal rotarymowing blades 163. The outwardly opening free ends of arms 26a areclosed by cover plates M4 to define an enclosed gear housing chamberItiiS at each end of the arms 26a; and the upper ends of stub shafts 162 and outer ends of shaft sections 36:: terminate in gear housings inmeshed bevel gears res and 107, the for or being rigidly connected tothe outer ends of shaft sections 36a for rotation therewith and thelatter bein rigidly connected to the upper ends of stub shafts 162, Thedrive means between depending shaft 26 and the mowing blades 1593 ofimplement heads 34: comprising shaft sections 36a, meshed bevel gears166 and M7, and stub shafts 132 drive implement heads 43a in the samedirection, as shown by the arrows in Fig, 8 for a single direction ofrotation of de pending shaft 2%.

Implement heads e351 generally underlie arms 26a and are rotatable aboutthe normally generally vertical axis of stub shafts 102 independent ofarm structure 24; and are further carried by arm structure 24 duringrotation thereof. I provide a pair of guard rings 108, one associatedwith each of the rotary implement heads 43a in upwardly spaced parallelaxially aligned relationship. Each of the guard rings 108 is rigidlyanchored to :a different one of the arms 26a by an elongated supportingbar 109. Bars 1&9 are rigidly anchored to the under side of :arms 2611,by welding or the like, and each intersects its associated guard ring1158 in the manner of a chord and is rigidly anchored thereto at suchintersections by welding or the like. Although implement heads 43a inthe modification of Figs. 8 and 9 have been shown to be mowing blades,implement heads 43a might comprise generally horizontal circular discshaving depending cultivating lugs rigidly anchored thereto.

The operation of this modification of my invention need not be furtherdescribed in view of the discussion of the operation of thefirst-described modification of my invention.

Referring now to the modification of my invention shown in Figs. 10-14,much of the structure is the same as particularly shown in Figs. 1, 2and 3. In this modification I provide a slightly different latchingarrangement and control means therefor; and this structure will bedescribed in detail. Elements of this modification which are exactly thesame or substantially the same as previously described in thedescription of Figs. l-7 will be given the same numerals as usedpreviously but will be distinguished by a prime mark. It is believedthat the preceding disclosure of the structure and operation of theother modifications of my invention will sufiice in many respects to actas a disclosure for this modification; and therefore, I shallspecifically describe hereinafter only that which is necessary to give athorough understanding of the features of this modification which differfrom the previously described modifications of my invention.

It should be particularly noted that in this modification I haveeliminated the supporting members 51 and 53 so that hub 25' of armstructure 24' adjoins the depending neck portion 49' of housing 16 andmay be journalled thereon for rotation with respect thereto.

I provide a pair of latching elements 110 and 111 which aresubstantially L-shaped bars or rods defining radially outwardlyprojecting latching arm portions 112 and 113, respectively, anddepending connecting portions 114, which at their lower ends are formedintegrally or rigidly connected to, by welding or the like, a collarmember 115 which encompasses depending neck portion 49' of housing 16'and is rigidly anchored by welding or the like to hub 25 of armstructure 24'. Latching elements 110 and 111 are disposed indiametrically opposed relationship to be circumferentially spaced 180with latched arm portions 112 and 113 thereof normally disposed incommon horizontal planes. It is clear that latching arm portions 112 and113 project radially outwardly in opposite directions and arecircumferentially spaced 180.

Housing 16 has a laterally offset supporting platform portion 116 whichis rigidly connected to and encompasses the outer end of tubular memberof supporting structure 19'. Bearing means comprising a nor mallygenerally vertically disposed bearing sleeve 117 is rigidly anchored, bywelding or the like, to the end of platform portion 116 in laterallyspaced parallel relationship to the axis of main shaft 20, see Fig. 3. Anormally generally vertically disposed rock shaft 118 is journalled inbearing sleeve 117 for pivotally swinging movements with respect tohousing 16 about a generally vertically disposed axis. Rock shaft 118projects above and below the limits of platform portion 116 and has athrust collar 119 formed therewith or rigidly anchored theretointermediate its ends, to maintain it properly journalled. I provide acooperating latching element 120 comprising a pair of like arms 121, seeFig. 11, rigidly connected adjacent one end of each thereof to the lowerend of rock shaft 118 in normally vertically spaced parallelrelationship, and a roller 122 disposed between arms 121 and connectedto the free ends thereof for rotational movement about a normallygenerally vertically disposed axis by a pivot pin or the like.Cooperating latching element 120 projects radially outwardly from rockshaft 118 and is normally disposed in substantially common planes withlatching arm portions 112 and 113. Cooperating latching element 120 isrigid with rock shaft 113 for pivotally swinging movements therewithinto and out of the path of travel of arm portions 112 and 113 oflatching elements and 111, which are rotatable with arm structure 24',between a latched position and an unlatched position, shown in full anddotted lines in Fig. 10 respectively. Cooperating latching element atits latched position is engageable with one or the other of the latchingelements 110 and 111 for locking arm structure 24 against rotation at anindexed position, as will be brought out more specifically subsequently.

I provide control means which includes a lever indicated generally bythe numeral 123. Lever 123 comprises a pair of spaced parallel elongatedbars 124 which are journalled at adjacent ends on the upper end of rockshaft 118, one on each side of end 125 of a control arm 126. Control arm126 is rigidly connected by welding or the like at its end 125 to theupper end of rock shaft 118. The free ends of bars 124 of lever 123 arepivotally connected to the outer end 127 of a piston 128 of any suitablepiston-cylinder-type shock absorber indicated by the numeral 129. Theother end of shock absorber 129, which is indicated by the numeral 130,is a part of or rigidly connected to the cylinder thereof and ispivotally connected to a supporting member 131 which is rigidly anchoredby welding or the like to a pair of brace members 132. Brace members 132at their opposite ends are rigidly anchored by welding or the like, totubular members 14' and 15 of supporting structure 10'. Resilient meanscomprising a tension spring 133 is disposed in parallel relationshipwith shock absorber 129 and is connected at its end 134 to lever 123adjacent the free end of one of the bars 124 and at its other end 135 isconnected to the adjacent one of the bars 132 of supporting structure10. Resilient means or tension spring 133 biases lever 123 to theposition shown in Fig. 10 which is its normal position.

I provide a connecting member between control arm 126 and lever 123which comprises a toggle indicated by the numeral 136. Referring inparticular to Fig. 14, toggle 136 comprises a pair of links 137 and 138pivotally connected at adjacent ends by pivot pin 139 or the like. Thefree end 140 of link 137 is disposed between the bars 124 of lever 123and is pivotally connected to lever 123, intermediate the ends thereofby pivot pin or bolt 141 or the like. Link 138, which may be a solidmember having bifurcated opposite ends, is shown as comprising a pair ofspaced parallel members. of toggle 136, which is the free end of link138 is pivotally connected to the free end 142 of control arm 126 bypivot pin or bolt 143 or the like. As shown in Fig. 14, free end 142 isdisposed between the spaced parallel members forming link 138. The formof lever 123 and toggle 136 herein shown disposes control arm 126,toggle 136 and lever 123 in substantially common planes even though thespaced bars 124 forming lever 123 and the spaced members forming link138 are offset from the horizontal planes of control arm 126 and link137 of toggle 136.

I provide a transverse stop finger rigidly connected to the spacedmembers of link 138, at the end thereof adjacent pivot pin 139, whichengages link 137 to limit relative pivotal movements of links 137 and138 in one direction from the fastening position of toggle 136 shown infull lines in Fig. 10. At the fastening position of toggle 136, links137 and 138 are at dead center and in substantially straight linerelationship as shown in full lines in Fig. 10. I provide yielding meanscomprising a.

The end tension spring 145 connected at one end to rock shaft 118,adjacent end 125 of control arm 126, and at its opposite end fastened toa buckle 146 which is disposed between the members of link 138 and rigily anchored thereto adjacent the pivotal connection of links 137 and138. Yielding means or tension spring 145 biases toggle 136 to the limitpermitted by stop finger 144, and, thereby, to its fastening position.

At the normal position of lever 123, see Fig. 10, and at the fasteningposition of toggle 136, shown in full lines in Fig. 10, cooperatinglatching element 128 is at its latched position; whereat, roller 122thereof is in engagement with the end of latching arm portion 113 andthis locks arm structure 24' against rotation about the axis of mainshaft 20, see Fig. 3. I provide operating means for moving toggle 136from its fastening position to a released position, shown in dottedlines Fig. 10, which together with toggle 136 provides means forcontrollably moving control arm 126 to move cooperating latching element120 from its latched position to its unlatched position. At the latter,cooperating latching element 120 is disposed out of the path of travelof latching arm portion 113, which will permit rotation of arm structure24'. The aforementioned operating means comprises a manually operatedlever 147, pivotally connected to supporting bar 11 of supportingstructure within easy reach of the tractor operator, and an elongatedflexible wire or the like. Wire 148 is connected at one end of lever147; it extends through a guide bracket 149 which is rigidly anchored tosupporting bar 11'; and it is connected at its opposite end to eyelet orring 150 which is rigidly anchored to link 138 adjacent buckle 146. Itis clear that a manual movement of the end of lever 147 which isopposite thereto, away from the tractor operator, or to its dotted lineposition shown in Fig. 10, will be transmitted through wire 148 to movetoggle 136, against the bias of tension spring 145, from its fasteningposition to its released position, shown in dotted lines in Fig. 10.This effects a relatively pivotal movement of links 137 and 138 from astraight line relationship to a transverse relationship which movescontrol arm 126 relatively toward lever 123, the latter being at itsnormal position. The movement of control arm 126 effects a rotation ofrock shaft 118 and thereby a pivotal movement of cooperating latchingelement 120 to its unlatched position. When the operator releases lever147, tension spring 145 will return toggle 136 to its fasteningposition, and thereby return cooperating latching element 120 to itslatched position.

The operation of this modification of my invention shown in Figs. 10-14,is very similar to the operation of the other modifications of myinvention, which has been described. Normally, the parts of my inventionare in the positions shown in full lines in Fig. 10. Lever 123 is at itsnormal position, toggle 136 is at its fastening position, andcooperating latching element 120 is at its latched position. Thus,normally my agricultural implement is operated for ordinary straightrunning with arm structure 24' locked against rotation at an indexedposition; however, impelement heads 43' are rotated independently of armstructure 24, in the manner disclosed with respect to my first describedmodification, for mowing or cultivating, depending upon which type ofimplement head is used, a generally straight swath. When an obstacle,such as a tree, post or the like is disposed within the path of myagricultural implement the operator will move lever 147 from its fullline position to its dotted line position just as the tree is closelyapproached, and prior to actual engagement of the tree with the armstructure 24'. This, as forementioned, effects the release of latchedengagement between cooperating latching element 120 and latching armportion 113 which permits the rotation of arm structure 24. The forceeffected by the rotation of implement heads 23', in opposite directions,

in engagement with the work rotates arm structure 24' in the directionindicated by the arrows in Fig. 10. Lever 147 is actuated onlymomentarily to effect the initial rotation of arm structure 24'; andupon its release, cooperating latching element is returned by the forceof tension spring to its latched position and in position to engagelatching arm portion 112 of latching element 110 in latched engagement.Latching element 110 and 111 are circumferentially spaced so that armstructure 24' will rotate 180 between the indexed positions. During therotation of arm structure 24, implement heads 43 rotate therewith 180about the obstacle, and together cultivate or trim approximately a full360 about the obstacle without stopping or slowing down the tractor.After one 180 cycle of rotation of arm structure 24, between two indexedpositions, my agricultural implement is again ready for ordinarystraight running.

After latched engagement of cooperating latching element 120 and one ofthe latching elements 110 and 111 has been released and arm structure24' is rotating about the axis of main shaft 20, the stopping of suchrotation by the engagement of the other of the latching elements 110 and111 with cooperating latching element 120 would effect considerablestrain upon latching element 120 without the control means I haveprovided. Specifically, stopping rotation of arm structure 24' puts atorque on latching element 120, tending to rotate it in the oppositedirection from the direction of rotation of arm structure 24. Thistorque is transmitted through rock shaft 118 to control arm 126 andthrough toggle 136 to lever 123 which is pivotally swingable about theaxis of rock shaft 118 from its normal position, Fig. 10, toward theposition thereof shown in Fig. 12. Shock absorber 129 absorbs the forceof impact of one of the latching elements 110 and 111 with cooperatinglatching element 120 upon the pivotal swinging movement of lever 123away from its normal position. After the impact, tension spring 133returns lever 123 to its normal position. It is clear that even withoutthe piston-cylinder-type shock absorber 129, tension spring 133 alonecould act to some extent as a shock absorber. I provide stop means,indicated generally by the numeral 151, rigidly connected to platformportion 116 of housing 16' which limits the pivotal movements of lever123 away from the normal position. Generally, the impact of one of thelatching elements 110 and 111 with cooperating latching element 120 isnot sufiicient to move lever 123 to the extent that it contacts the stopmeans or buffer 151; however, should the impact be of such an extent,cooperating latching element 120 is moved to its unlatched position whenlever 123 engages the stop means 151. This releases the latchingengagement of cooperating latching element 120 and one of the latchingelements 116 and 111 and prevents any damage to the structure that mightbe ocasioned by such an impact. In addition, should one of the implementheads 43 engage an obstacle such as a rock or the like, this will effecta load on the arm structure 24 which will be transmitted to lever 123 topivotally swing it enough to engage the buffer or stop means 151, andthereby move cooperating latching element 120 to its unlatched positionand permit the rotation of arm structure 24'. In this manner, theobstacle, which has put the load on the arm structure 24, will beavoided and damage to the structure is completely prevented. It is clearthat after arm structure 24' has begun to rotate to avoid the obstacle,tension spring 133 will return lever 121 to its normal position, andcooperating latching element 120 will be returned to its latchedposition to again lock arm structure 24' against rotation after a 180cycle rotation thereof.

Referring in particular to Fig. 13, I show a preferred form of stopmeans 151. An L-shaped bracket 152 is rigidly anchored to supportingplatform portion 116 by bolts or the like extending through elongatedslots 153.

In this manner, stop means or buffer 151 may be adjusted with respect tolever 123 to shorten or lengthen the pivotal swing thereof. An outwardlyopening tubular member 154 extends through and is rigidly anchored tothe upstanding flange of bracket 152, and it is adapted totelescopically receive a similar open ended tube member 155. Acompression spring 156 is connected at its opposite ends to theoppositely disposed closed ends 157 and 158 of tube members 155 and 154,respectively. A guide sleeve 159 is rigidly anchored, by welding or thelike, at one end to the upstanding flange of bracket 152 and encompassestube members 154 and 155 adjacent the telescopic connection thereof toguide tube member 155 for longitudinal movement toward and away from thebracket 152. It is clear that the longitudinal movement of tube member155 toward bracket 152 moves tube member 154 inwardly with respectthereto to retract the telescopic relationship of tube members 154 and155; and this retraction is against the bias of compression spring 156.This arrangement acts as an excellent buffer to take up the shock ofimpact of lever 123 with stop means 151. I provide an annular fiat pad160 of rubber or the like connected to the outer closed end 157 of tubemem' her 155.

A particular feature of this modification of my invention is the factthat supporting platform portion 116 is disposed between all of thecontrol linkage for cooperating latching element 120 and the groundwhich is being worked by the implement heads 43. This prevents any dirt,or other matter, from being thrown up from the ground into the linkage,e. g. toggle 136, lever 123 and control arm 126; and this prevents anyclogging of the control mechanism of my invention and insures the properoperation thereof at all times. Platform portion 116, in effect, acts asa guard plate between the control mechanism of my invention and theground being worked by the implement heads 43.

Implement heads 43' as shown in this modification of my invention arethe same as and operated in the same manner as implement heads 43,described in the description of the first modification of my invention;however, it is clear that this modification of my invention may bemodified in the same manner that the modification shown in Figs. 8 and 9modifies the first described modification of my invention.

My invention, including all the modifications thereof hereinshown anddescribed, has been built and tested and found to accomplish all of theaforementioned objectives and advantages, and to be highly desirable andcommercially practical as an agricultural implement. It will be obviousto those skilled in the art that my invention may be modified by manysubstitutions and equivalents and that this disclosure is intended to beillustrative only; therefore, I intend to be limited solely by the scopeof the appended claims.

What I claim is:

1. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor to be normally carried in a laterallyoutwardly projecting position, a normally vertically disposed shaftjournalled in said supporting structure for rotation about a normallygenerally vertically disposed axis, arm structure including a pair ofnormally generally horizontally disposed interconnected aligned armswhich project radially outwardly in opposite directions with respect tothe axis of said shaft, means journalling said arm structure forrotation about the axis of said shaft, a pair of implement heads onebeing connected to each of said arms for rotational movement therewithand for rotational movement independent thereof, drive-train meansconnecting said shaft and each of said implement heads for rotating saidheads independent of said arm structure, the independent rotation ofsaid heads being in directions cooperating to tend to rotate said armstructure about the axis of said shaft in one direction, releasableindexing means for selectively 14 locking said arm structure againstsaid last mentioned rotation, and control means being actuated to permitsaid rotation of said arm structure about the axis of said shaft betweentwo indexed positions.

2. The structure defined in claim 1 in which said indexing means is aspring detent mechanism comprising a pair of cooperating elements onebeing connected to said arm structure and the other to said supportingstruc ture, the latter being disposed in the path of travel of theformer to lock said arm structure at an indexed position, and one ofsaid cooperating elements being selectively movable with respect to theother permitting rotational movement of said arm structure past saidindexed position.

3. The structure defined in claim 1 in which said releasable indexingmeans comprises spring-biased detent mechanisms having cooperatinglatching elements connected to said arm structure and said supportingstructure for selectively locking said arm structure against rotation atpositions circumferentially spaced 180.

4. The structure defined in claim 1 in which said drive train meansinclude a pair of normally generally horizontally disposed axiallyaligned shafts each being journalled in a different one of said arms forrotation with respect thereto, said generally horizontal shafts havingadjacent ends connected with the lower end of said vertical shaft sothat rotation of said vertical shaft in one direction drives. saidhorizontal shafts in opposite directions.

5. The structure defined in claim 4 in which said implement headscomprise generally elongated tubular structures disposed in axiallyaligned relationship, each head encompassing a different one of saidarms in concentric relationship with the shaft journalled therein, andmeans rigidly connecting each head to the shaft concentric with it forrotational movement therewith about a horizontal axis.

6. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor to be normally carried in a laterallyoutwardly projecting position, a normally vertically disposed shaftjournalled in said supporting structure for rotation about a normallygenerally vertically disposed axis, arm structure comprising a hubencompassing the lower part of said shaft and journalled thereon forrotation with respect thereto about the axis of said shaft and a pair ofnormally horizontally disposed arms anchored to said hub in radiallyoutwardly projecting diametrically opposed relationship, a pair ofvertically disposed stub shafts each connected to said arm structure forrotation therewith adjacent the free end of a different one of saidarms, means journalling said stub shafts for rotation about generallyvertical axes independent of said arm structure, a pair of generallyhorizontally disposed implement heads each anchored to a different oneof said stub shafts for rotation therewith generally underlying said armstructure, drive means connecting said first-mentioned vertical shaftand each of said vertical stub shafts for rotating said implement headsin the same direction independent of said arm structure, the rotation ofsaid heads in the same direction tending to rotate said arm structureabout the axis of said shaft releasable indexing means for selectivelylocking said arm structure against rotation, and control means beingactuated to permit rotation of said arm structure bewteen two indexedpositions.

'7. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor to be normally carried in a laterallyoutwardly projecting position, a normally vertically disposed shaftjournaled in said supporting structure for rotation about a normallygenerally vertically disposed axis, arm structure including a pair ofnormally generally horizontally disposed interconnected aligned armswhich project radially outwardly in opposite directions with respect tothe axis of said shaft, means journalling said arm structure forrotation about the axis asaenaa of said shaft, a pair of implement headsone being connected to each of said arms for rotational movementtherewith and for rotational movement independent thereof, drive-trainmeans connecting said shaft and each of said implement heads forrotating said heads independent of said arm structure, the independentrotation of said heads being in directions cooperating to tend to rotatesaid arm structure about the axis of said shaft in one direction,releasable indexing means comprising a pair of cooperating elements onebeing connected to said arm structure and the other to said supportingstructure, one of said elements being pivotally swingable into and outof the path of relative movement of the other between a latchingposition and an inoperative position, and automatic control meansbiasing said movable element to its latching position and being actuatedby an impact force to move said movable element to its inoperativeposition and permit rotation of said arm structure between two indexedpositions.

8. The structure defined in claim 7 in which said con trol meanscomprises a spring-biased toggle, a normally generally horizontalelongated rod pivotally connected to the same structure as said movablelatching element to be disposed forwardly of said arm structuregenerally normal to said tractor when said latching elements are inlatched relationship at an indexed position, and an actuating pinanchored to said rod in longitudinally spaced relation to the pivot axisthereof for pivotal swinging movements with said rod to engage and movesaid toggle.

9. The structure defined in claim 8 in which said drivetrain meansincludes a pair of normally generally horizontally disposed axiallyaligned shafts each being journalled in a dilferent one of said arms forrotation with respect thereto, and said implement heads comprisegenerally elongated tubular structures disposed in axially alignedrelationship, each head encompassing a different one of said arms inconcentric relationship with the shaft journalled therein, and meansrigidly connecting each head to the shaft concentric with it forrotational movement therewith about a horizontal axis.

10. The structure defined in claim 8 in which said drive-train meanscomprises a pair of vertically disposed stub shafts eacn connected tosaid arm structure for rotation therewith adjacent the free end of adifferent one of said arms, said stub shafts being journalled forrotation about generally vertical axes independent of said armstructure, and said implement heads are generally horizontally disposedand each is anchored to a different one of said stub shafts for rotationtherewith generally underlying said arm structure.

ll. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor and comprising a generally horizontallydisposed laterally outwardly projecting tubular member and a housing atthe free end of said member, a drive shaft journalled for rotation insaid tubular member and adapted to be driven from the tractor take-off,a normally generally vertically disposed depending shaft journalled insaid housing for rotation about a normally generally vertically disposedaxis, gearing in said housing connecting said depending shaft to saiddrive shaft to be driven thereby, arm structure comprising a hubencompassing the lower part of said depending shaft and journalledthereon for rotation with respect thereto and a pair of normallyhorizontally disposed arms anchored to said hub in radially outwardlyprojecting diametrically opposed relationship, a. pair if implementheads one being connected to each of said arms for rotational movementtherewith and for rotational movement independent thereof, drive-trainmeans connecting said shaft and each of said implement. heads forrotating said heads independent of said arm structure, the independentrotation of said heads being in directions cooperating to tend to rotatesaid arm struc ture about the axis of said depending shaft in onedirection, releasable indexing means comprising spring-biased detentmechanisms having cooperating latching elements connected to said armstructure and said supporting structure for selectively locking said armstructure against said rotation about the axis of said depending shaftat positions circumferentially spaced and control means being actuatedto permit rotation of said arm structure about the axis of saiddepending shaft between two indexed positions.

12. The structure defined in claim 11 in which said releasable indexingmeans comprises a pair of latching elements connected to said armstructure in 180 circumferentially spaced relationship for movementtherewith, said latching elements being pivotally swingable betweenlatching positions and inoperative positions, a pair of spring-biasedtoggles connected to said arm structure and each being pivotallyconnected to a different one of said latching elements for normallymaintaining said latching elements at their latching position, acooperating latching element connected to said supporting structure andnormally disposed in the path of travel of said first-mentioned pair oflatching elements when the latter are in their latching positions, apair of normally generally horizontally disposed laterally spacedparallel rods pivotally connected to said arm structure, each rod beingpivotally swingable toward and away from a different one of said togglesand adapted to be disposed forwardly of said implement heads andgenerally normal to said tractor when the latching element pivotallyconnected to the toggle toward which said rod is movable is in latchedrelationship with the cooperating element connected to the supportingstructure, and actuating pins one anchored to each of said rods inlongitudinally spaced relation to the pivot axis thereof for pivotalswinging movements with said rod to engage and move the adjoining togglewhereby to release the latched relationship of one latching element andthe cooperating element and permit rotation of said arm structure 180wherein the other latching element and said cooperating element engagein latched relationship.

13. The structure defined in claim 12 in which said cooperating elementconnected to the supporting structure is pivotally connected thereto forswinging movements into and out of the path of travel of said pair oflatching elements between a latched position and an unlatched position,in further combination with manual control means for moving saidlast-mentioned cooperating elemeat.

14. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor to be normally carried in a laterallyoutwardly projecting operative position, a normally generally verticallydisposed main shaft journalled in said supporting structure for rotationabout a generally vertically disposed axis and adapted to be driven fromthe power take'clf of said tractor, arm structure including a pair ofgenerally horizontally disposed interconnected aligned arms whichproject radially outwardly in opposite directions with respect to theaxis of said main shaft, means journalling said arm structure forrotation about the axis of said main shaft, 8. pair of implement headseach being connected to a different one of said arms for rotationalmovement therewith and for rotational movement independent thereof,drive-train means connecting said main shaft with each of said implementheads for rotating said heads independent of said arm structure, theindependent rotation of said heads being in directions cooperating totend to rotate said arm structure in one direction about the axis ofsaid main shaft, a pair of circumferentially spaced latching elementsrigid with said arm structure and rotatable therewith about the axis ofsaid main shaft, a rock shaft connected to said supporting structure forrotational movements with respect thereto, a cooperating latchingelement rigid with said rock shaft for pivotally swinging movementstherewith into and out of the path of travel of said pair of latchingelements between a latched position and an unlatched position, saidcooperating latching element at its latched position being engageablewith one of said pair of latching elements for locking said armstructure against rotation at an indexed position, and control meanscomprising a lever journalled adjacent one end on said rock shaft forpivotally swinging movements about the axis thereof from and back to anormal position, resilient means connectedtadjacent the free other endof said lever and to said supporting structure for biasing said lever toits normal position, a control arm rigid with said rock shaft, aconnecting member having one end pivotally connected to said control armand having its opposite end pivotally connected to said leverintermediate the end thereof, whereby torque applied to said cooperatinglatching element by a force in the same direction as the direction ofrotation of said arm structure is transmitted to said control arm .andthrough said connecting member to said lever which tends to move saidlever from its normal position against the bias of said resilient meansand whereby the pivotally swinging movements of said lever against thebias of said resilient means absorbs the shock of the engagement of saidcooperating latching element with one of said pair of latching elementsand under sufficient torque said lever will move from its normalposition sufiiciently to move said cooperating latching element to itsunlatched position, and means for controllably moving said control armto move said cooperating latching element between its latched andunlatched position to permit rotation of said arm structure past oneindexed position.

15. The structure defined in claim 14, in which said connecting memberis a toggle comprising a pair of pivotally connected links, in furthercombination with yielding means biasing said toggle just past deadcenter toa fastening position, wherein at the normal position of saidlever and the fastening position of said toggle said cooperatinglatching element is at its latching position, and operating meansconnected to said toggle adjacent the pivotal connection of the linksthereof for moving said toggle against the bias of said yielding meanspast dead center to a released position, said operating means to getherwith said toggle comprising the aforementioned means for controllablymoving said control arm to move said cooperating latching elementbetween its latched position and its unlatched position.

16. The structure defined in claim 15, in which said pair of latchingelements are circumferentially spaced 180.

17. The structure defined in claim 16, in further combination with apiston-cylinder-type shock absorber disposed'in parallel with saidresilient means and having one end connected to said supportingstructure and the other end connected to the free end of said lever.

18. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor to be normally carried in a laterallyoutwardly projecting operative position; a normally generally verticallydisposed main shaft journalled in said supporting structure for rotationabout a generally vertically disposed axis and adapted to be driven fromthe power take-off of said tractor; arm structure including a pair ofnormally generally horizontally disposed inter-connected aligned armswhich project radially outwardly in opposite directions with respect tothe axis of said shaft; means journalling said arm structure forrotation about the axis of said main shaft; a pair of implement headseach being connected to a different one of said arms for rotationalmovement therewith and for rotational movement independent thereof;drive-train means connecting said main shaft with each of said implementheads for rotating said heads independent of said arm structure, theindependent rotation of said heads being in directions cooperating totend to rotate said arm structure in one direction about the axis ofsaid main shaft; a pair of latching elements disposed in 180circumferentially spaced relationship with each other, and each beingrigid with said arm structure and rotatable therewith about the axis ofsaid main shaft;a normally generally vertically disposed rock shaftconnected to said supporting structure in laterally spaced parallelrelation to the axis of said main shaft for rotational movements withrespect to said supporting structure about a normally generallyvertically disposed axis; a cooperating latching element rigidlyconnected to the lower end of said rock shaft and projecting radiallyoutwardly therefrom, said cooperating latching element beingpivotallyswingable with said rock shaft into and out of the path of travel ofsaid pair of latching elements between .a latched position and anunlatched position wherein at the former said cooperating latchingelement is engageable with one of said pair of latching elements forselectively locking said arm structure against rotation at an indexedposition and at the latter said arm structure is free to rotate aboutthe axis of said main shaft; and control means comprising a normallygenerally horizontally disposed lever having one end journalled on saidrock shaft adjacent the upper end thereof for pivotally swingingmovements about the axis of said rock shaft from and back toa normalposition, resilient means connected adjacent the free other end of saidlever and to said supporting structure for biasing said lever to itsnormal position, stop means rigidly connected to said supportingstructure limiting the pivotal movements of said lever away from itsnormal position, a control arm rigidly connected to said rock shaftadjacent the upper end thereof transversely disposed with respect tosaid cooperating latching elementand-disposed in substantially commonplanes with said lever, a normally generally horizontally disposedtoggle adjoining said control arm and said lever in substantially commonplanes and comprising a pair of links having adjacent ends pivotallyconnected and being pivotally connected at the free end of one of saidlinks to the free end of said control arm and pivotally connected at thefree end of the other link to said lever intermediate the ends thereof,yielding means biasing said toggle just past dead center to a fasteningposition at which position said control arm and said toggle and one endportion of said lever form substantially a triangle whereby torqueapplied to said cooperating latching element by a force in the samedirection as the direction of rotation of said arm structure istransmitted to said control arm and through said toggle to said leverwhich tends to move said lever from its normal position against the biasof said resilient means toward said stop means and whereby .thepivotally swinging movements of said lever against the bias of said,resilient means absorbs the shock of the engagement of said cooperatinglatching element with one of said pair of latching elements and undersufficient torque said lever will move from its normal positionsufficiently to engage said stop means at which position saidcooperating latching element is moved to its unlatched position, andoperating means connected to said toggle adjacent the pivotal connectionof the links thereof for moving said toggle against the bias of saidyielding means past dead center to a released position for controllablymoving said control arm from its latched position to its unlatchedposition to permit rotation of said arm structure past one indexedposition, whereby upon release of said operaing means said yieldingmeans returns said toggle to its fastening position which moves saidcooperating latching element to a latching position to be engaged by theother of said pair of latching elements.

19. In a rotary agricultural implement, supporting structure adapted tobe connected to a tractor and comprising a generally horizontallydisposed laterally outwardly projecting tubular member and a housing atthe free end of said member; a drive shaft journalled for rotation insaid tubular member and adapted to be driven from the power takeoff ofsaid tractor; a normally generally vertically disposed depending mainshaft journalled in said housing adjacent its upper end for rotationabout a normally generally vertically disposed axis; gearing in saidhousing connectng said depending main shaft to said drive shaft to bedriven thereby; arm structure comprising a hub encompassing the lowerpart of said depending main shaft and journalled thereon for rotationwith respect thereto and a pair of normally horizontally disposed armsrigidly anchored to said hub in radially outwardly projectingdiametrically opposed relationship; a pair of implement heads each beingconnected to a different one of said arms for rotational movementtherewith and for rotational movement independent thereof; drive-trainmeans connecting said main shaft and each of said implement heads forrotating said heads independent of said arm structure, the independentrotation of said heads being in directions cooperating to tend to rotatesaid arm structure in one direction about the axis of said main shaft;said housing having a laterally offset supporting platform portion; anormally generally vertically disposed rock shaft projecting above andbelow the offset platform portion of said housing in laterally spacedparallel relationship to the axis of said main shaft; bearing meansconnecting said rock shaft to said platform portion for rotationalmovements about a normally generally vertically disposed axis; a pair oflatching elements rigidly anchored to said arm structure and rotatabletherewith about the axis of said main shaft each having a latching armportion projecting radially outwardly which are disposed in 180circumferentially spaced relationship with respect to each other; acooperating latching element rigidly connected to the lower end of saidrock shaft and projecting radially outwardly therefrom and disposed insubstantially common planes with said latching arm portions, saidcooperating latching element being pivotally swingable with said rockshaft into and out of the path of travel of said pair of latchingelements between a latching position and an unlatched position whereinat the former said cooperating latching element is engageable with oneof said latching arm portions for selectively locking said arm structureagainst rotation at an indexed position and at the latter said armstructure is free to rotate about the axis of said main shaft; andcontrol means comprising a normally generally horizontally disposedlever overlying said supporting platform portion and having one endjournalled on said rock shaft at the upper end thereof for pivotallyswinging movements about the axis of said rock shaft from and back to anormal position, resilient means connected adjacent the free other endof said lever and to said supporting structure for biasing said lever toits normal position, stop means rigidly connected to said supportingstructure limiting the pivotal movements of said lever away from itsnormal position, a control arm rigidly connected to said rock shaftadjacent the upper end thereof transversely disposed with respect tosaid cooperating latching element and disposed in substantially commonplanes with said lever, a normally generally horizontally disposedtoggle adjoining said control arm and said lever in substantially commonplanes and comprising a pair of links having adjacent ends pivotallyconnected and being pivotally connccted at the free end of one of saidlinks to the free end of said control arm and pivotally connected at thefree end of the other link to said lever intermediate the ends thereof,yielding means biasing said toggle just past dead center to a fasteningposition at which position said control arm and said toggle and one endportion of said lever form substantially a triangle whereby torqueapplied to said cooperating latching element by a force in the samedirection as the direction of rotation of said arm structure istransmitted to said control arm and through said toggle to said leverwhich tends to move said lever from its normal position against the biasof said resilient means toward said stop means and whereby the pivotallyswinging movements of said lever against the bias of said resilientmeans absorbs the shock of the engagement of said cooperating latchingelement with one of said pair of latching elements and under sufiicienttorque said lever will move from its normal position sufiiciently toengage said stop means at which position said cooperating latchingelement is moved to its unlatched position, and operating meansconnected to said toggle adjacent the pivotal connection of the linksthereof for moving said toggle against the bias of said yielding meanspast dead center to a released position for controllably moving saidcontrol arm from its latched position to its unlatched position topermit rotation of said arm structure past one indexed position, wherebyupon release of said operating means said yielding means returns saidtoggle to its fastening position which moves said cooperating latchingelement to its latching position to be engaged by the other of said pairof latching elements.

20. The structure defined in claim 19 in further combination with apiston-cylinder-type shock absorber disposed in parallel with saidresilient means and having one end connected to said supportingstructure and the other end connected to said free other end of saidlever.

References Cited in the file of this patent UNITED STATES PATENTS2,421,558 Goldsmith June 3, 1947 2,668,488 Shimmon Feb. 9, 19542,732,675 Smith et al. Ian. i, 1956

